NiCoP self-supporting electrode with the sea urchin-like microstructure for the synchronous reaction of hydrogen evolution and contaminant degradation

The development of an earth-rich and efficient and stable electrocatalyst is the key to achieving efficient hydrogen production from electrolysis of water. In energy-saving hydrogen production, the oxygen evolution reaction in the electrolysis of water is often another important factor that restricts efficient hydrogen production. Therefore, in this study, we used carbon cloth as the base of the self-supporting electrode. Nickel and cobalt, rich non-noble metals, were introduced to the carbon cloth through a simple hydrothermal reaction. The composite phosphides of nickel and cobalt were obtained by low-temperature phosphating. The prepared materials possess a sea urchin-like microstructure which is composed of microspheres in center and nanospines on its surface. Based on this unique sea urchin-like structure, NiCoP/CC self-supporting electrode exhibits a good hydrogen evolution performance in acidic solutions. The required overpotentials were only 178 mV and 395 mV vs RHE at 10 and 100 mA cm-2, respectively. We used this NiCoP/CC self-supporting electrode as the cathode and the pure CC as the anode. Under the condition of a constant current density of 2 mA cm-2, the degradation efficiency of methylene blue at 90 min was 88% and hydrogen was produced constantly on the NiCoP/CC self-supporting electrode, which provided an idea for the combination of hydrogen evolution reaction and organic matter degradation.

Automated summary

In this study, a self-supporting electrode with a sea urchin-like microstructure of NiCoP/CC was prepared by introducing nickel and cobalt into carbon cloth through a simple hydrothermal reaction and low-temperature phosphating. The self-supporting electrode showed excellent hydrogen evolution performance in acidic solutions, and demonstrated efficient degradation of methylene blue while producing hydrogen constantly, providing a promising approach for combining the hydrogen evolution reaction with organic matter degradation.